Tuesday, March 3, 2015

Megafauna



Baz Edmeades (“ed-meedz.”) grew up in South Africa.  His grandfather, Thomas F. Dreyer, was the paleontologist who discovered an unknown species, Homo helmei.  The new species was an immediate predecessor of Homo sapiens, and it lived 239,000 years ago — in Africa!  Europeans, the self-elected master race, naturally assumed that humankind emerged somewhere closer to London.  White folks were shocked to realize that they were (gulp!) Africans.

South Africa’s Kruger National Park is home to megafauna (large animals) that once inhabited vast regions of the world.  Sadly, poachers have been pushing a number of species close to extinction.  This drove Edmeades crazy.  It inspired him to begin research on a book that became Megafauna — First Victims of the Human-caused Extinction.

During the project, he became friends with Paul Martin, who strongly influenced his thinking.  Martin was the father of the Pleistocene overkill hypothesis, which asserted that overhunting was the sole cause for the megafauna extinctions in North and South America.  They occurred after humans crossed into the Americas from Siberia, 15,000 to 20,000 years ago.

Other scholars disagreed.  They blamed climate change, and its effects on vegetation.  But the extinct species had previously survived a number of big climate swings.  Still others blamed disease, a comet strike, or a combination of factors.  The issue is highly complex, and there is currently insufficient evidence to unify the experts, and drive the controversy extinct.

On every continent except Antarctica, there were spasms of megafauna extinctions.  They occurred in different regions, at different times, not in synch with climate swings.  There is real evidence that humans were not innocent bystanders in these murder mysteries.  They likely played a primary role.

In Australia, some say that the species driven to extinction 50,000 years ago were victims of the newly arrived humans.  On the islands of New Zealand, Tasmania, Hawaii, Tonga, Madagascar, the Caribbean, and the Mediterranean, extinctions occurred at different times, following the appearance of humans.

Much earlier, Africa suffered a severe spasm of extinctions, long before Homo sapiens.  The continent was loaded with megafauna 1.8 million years ago, but many were gone by 1.4 million years ago.  There used to be nine species of big cats (three today), nine types of elephants (one today), four hippos (one today).  There were giant antelopes, giant hyenas, giant pigs, giant monkeys, and giant baboons, all gone.  

Some, including Edmeades, blame overhunting.  At the time, our ancestor Homo erectus had been busy, inventing a new and improved toolbox — knives, saws, axes, cleavers.  This was the Acheulian revolution.  They knew how to use fire, and they may have been the first to use the wooden spear.

In North America, when humans arrived, there were at least nine species of big cats, and seven species of elephants.  The biodiversity was incredible — beavers as big as bears, two-ton buffaloes, armadillos the size of VW Beetles.  Until 14,000 years ago, mammoth country ranged from Western Europe to Mexico.  Aurochs ranged from England to Korea, and south to India and North Africa.  Rhinos ranged from Europe to Sumatra.  Under downtown London are the remains of hippos, elephants, giant deer, aurochs, and lions, residents of the thriving rainforests of England. 

Prior to the spear, our ancestors had been similar to baboons and chimps, scavenging lunch from carnivore kills, and bludgeoning small critters like monkeys and lizards.  Over many thousands of years, evolution had gradually made us better hunters.  Changes to our bones and muscles improved our ability to accurately hurl projectiles, and kill from a distance.  Evolution also improved our long distance running skills.  Our ancestors were much slower than antelopes, but we could chase them for hours, until they collapsed from exhaustion.

Before the spear, we acquired new abilities very slowly, by evolving.  At the same time, other species were also busy evolving new abilities for countering our advances, and maintaining the balance.  With our transition to tool making, we began gaining new abilities by inventing them, a far quicker process.  Spears enabled our ancestors to subdue the man-eating predators who kept them from exploding in numbers.  This rubbished the laws of nature.  Imagine rabbits inventing tools that allowed them to overpower foxes.  With spears, we could also kill large game, acquire abundant meat, and feed more bambinos.

Like the trend of population growth, the trend of techno innovation proceeded slowly for ages, until exploding in recent times.  Innovation allowed us to temporarily sneak around the checks and balances of evolution, and discover the painful consequences of violating the laws of nature in a giddy whirlwind of blissful ignorance.  We invented the ability to disrupt the balance of nature.

All wild animals live in the here and now, paying acute attention to the immediate vicinity.  None devote attention to the balance of nature, or to risks that may arise in the future.  If they get food, they eat; if not, they starve.  Amazingly, some tool-making societies eventually developed a sense of foresight.  They practiced enlightened self-restraint, which included taboos on overhunting and overbreeding — never-ending responsibilities.  Foresight was a slippery path, and some groups slid into domestication.  Unfortunately, societies that master self-restraint are helpless sitting ducks when discovered by civilization — a serious and perplexing predicament.

What really captured my attention while reading, was realizing the incredible abundance of huge, beautiful, powerful forms of life that once thrived on Earth.  It’s almost impossible to imagine how spectacularly alive and healthy this planet was in the days before the toolmakers.  Today, it feels like we’re living in desolate ghost towns, nothing but humans.  I can walk alone all night without fear of being eaten.  Our soundtrack is the rumbling, roaring, screeching noise of planet-eating machinery — not wolves, hyenas, elephants, elk — the wild music of a wild land.

And so, here we are.  We have unluckily inherited a treasure chest of predicaments, all getting worse.  Do you think we can somehow find a way to return to ecological harmony by continuing down the path of technology — solar panels, wind turbines, nanotechnology, space exploration, computer-driven cars?

Our closest relatives, the chimps and bonobos, with whom we share 98 percent of our DNA, provide excellent examples of the benefits of living in compliance with the laws of nature.  They’ve lived in the same place for two million years without trashing it.  Humans who study the school of life can survive in tropical forests without tool making, but seven billion can’t.

Cultures die.  The culture of endless growth and insatiable consumption is moving into its twilight years, as resource limits draw the curtains closed.  A muscle-powered future will require a muscle-powered culture.  We could resurrect the unsustainable cultures of centuries past, and repeat their blunders.  Or, we could learn from their mistakes and try something different and better — like rejoining the family of life, and obeying the laws of nature.  Imagine that.  What can we do to move in that direction?

Anyway, Edmeades provides a long and fascinating discourse on megafauna extinctions.  Megafauna is an unfinished work in progress (as of February 2015).  The manuscript has not been copyedited, but the text is well written, easy for general readers to understand.  Edmeades’ deep knowledge of paleontology is obvious.  This is an important document.

Edmeades, Baz, Megafauna — First Victims of the Human-caused Extinction, 2013.  This fascinating manuscript has been withdrawn from its home location (megafauna.com) for updates.  An earlier version is available HERE.

In 2013, the Caustic Soda program produced a slightly-serious interview with Edmeades, a 75-minute podcast.

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